In order to attach a metal fitting, such as a threaded connection, to a flexible rubber hose it is necessary to assemble the metallic fitting and the hose into their proper positioning and then to crimp the metallic fitting around the hose to form a tight connection that will not permit leakage of the fluid carried in the hose. The crimping action involves a high pressure pinching or swaging of the metal sleeve, reducing the diameter of the sleeve so as to form a tight connection with the rubber hose. The pinching or the swaging action has been performed in the past in many ways, including a drop-hammer pounding the metal of the fitting while it is resting against an anvil. More recently the use of hydraulic pressure devices have permitted the same action to occur through a single stroke of a high pressure ram against a collet wherein a plurality of metal fingers are pressed inwardly around the outer surface of the metallic fitting that is to be crimped. The structure of such a collet is normally a cylindrical or frustoconical member divided into a plurality of individual sectors around a central axial bore. The sectors are spaced apart from each other in the expanded mode so as to permit the metallic fitting which is to be crimped to be placed in the central bore. The sectors are then compressed in radial directions so as to make the central bore smaller causing the fingers of the sectors to work the metal fitting and to reduce its diameter. In this fashion the metal fitting can be crimped upon a flexible hose or other article to which the fitting is to be attached. Such collets have been produced in the past with many types of devices for holding the several sectors together into a single compressible unit. Combinations of springs, levers, and screws have been employed in the past to hold the assembled unit in an expanded condition and yet to permit the unit to contract when subjected to radial forces.
It is an object of this invention to provide an improved crimping collet. It is another object of this invention to provide an improved method of holding a multi-sectored collet together in a compressible condition. It is still another object of this invention to provide an improved frustoconical collet to be employed with a hydraulic ram system. Still other objects will be apparent from the more detailed description of this invention which follows.